1. Field of the Invention
The present invention relates to an electrically powered or manually operable clutch and brake assembly for an electric winch, particularly to a new design of a clutch mechanism, a brake mechanism and a transmission mechanism used in the electric winch.
2. Description of the Prior Art
A conventional electric power driven winch uses a transmission mechanism and a rotating shaft of a motor to drive a large clutch gear which is provided with a lining plate. The lining plate is coupled with a clutch pinion gear which is used to drive the transmission mechanism so that a shaft can be rotated to pull a heavy load. When the motor stops running, a ratchet-type component is used to retain the large clutch gear and generate a braking force so as to prevent the heavy load from reverse movement. However, the conventional electric power driven wince has the following drawbacks:
(1) A locking nut is used to push the large and pinion gears of the clutch together tightly, forcing lining plates provided between the clutch plates to push against each other. However, it is common to have vibration in the winch during operation, causing the locking nut to retreat and loosen due to such vibration. PA1 (2) The locking nut used to tighten the large and pinion gears is applied in the axial direction, forcing the lining plate provided on the surface of the clutch plate to push tightly against the pinion gear. This direct pushing by the locking nut does not provide any cushion for the large and pinion gears of the clutch. Thus, thrust bearings on opposite sides of the gears have to bear a heavy load, causing them to wear out quickly. This also means that the wince will have a more troubled operation and will require more maintenance.